Abstract: The microstructure of soil is the internal factor determining its engineering properties, especially the pore characteristics of soil. It is an important index reflecting the state and strength of soil. In order to further understand the engineering geological characteristics of the saline soil in Western Jilin Province, the pore characteristics and influencing factors of different depth saline soil in Nong'an area are studied by using the mercury intrusion method. The results show that:The porosity of the soil increases with the increase of depth, and the distribution of pores at different depths is different. According to the fractal theory, the distribution of pores has fractal characteristics, and the fractal dimension D of pores increases with the increase of depth. The pores of saline soil in the study area were divided into three grades:macropores(d30m),mesopores(7m d 30m), and small pores(d7m). The physicochemical properties of soil affect each other and decide their pore characteristics together, thus affecting their engineering geological properties. The results can provide a basis for exploring the strength mechanism of saline soil in Western Jilin Province.